ORM Templates

Concepts

ORM (Object Relational Mapping) is an Object Oriented software design pattern which implies the mapping of database relations (tables) into classes.

With ORM two other design patterns are often used:

• DO (Data Object): definition of a class which provides mapping of a relation instance (record) into an object instance;
• DAO (Data Access Object): definition of a class to interact with a given relation (table), which encapsulates the querying process, providing the user a complete Object Oriented interface, using Data Object instances and collections.

More about ORM on Wikipedia.

Usage

This repository contains DO and DAO classes + DBConnector, a class used to ease the interaction with MySQL for basic PHP applications.
The DBConnector class must be used to instantiate a database connection.
You can define Data Object and Data Access Object classes for your own application data by extending the DataObject and DataAccessObject classes.
Your Data Object class must redefine a few methods like so:

class  MyDataObject extends DataObject{
    private $field1;
    private $field2;

    public function __construct($field1,$field2){
        //your ctor code here
    }

    public static function fromArray(array $fields) {
        //return a MyDataObject instance constructed from an associative array
    }

    public function getField1(){
        //getter code here
    }

    public function setField1($field1){
        //setter code here
    }

    public function getArray() {
        //return an associative array representing the MyDataObject instance
    }

    public function getPrimaryKey(){
        //return an associative array corresponding to the current MyDataObject instance primary key
    }
    
    public function getFields(){
       //return an associative array corresponding to the current MyDataObject instance fields, primary key excluded
    }

}

Your Data Access Object class must be defined as follows:

class MyDataAccessObject extends DataAccessObject{

    public function __construct(DBConnector $conn,$tableName) {
        //pass your custom Data Object class to the DataAccessObject constructor
        parent::__construct($conn,$tableName,MyDataObject::class);
    }

    //custom methods here

}

Methods for INSERT, UPDATE, DELETE and generic SELECT with basic WHERE...AND... filter are already implemented in the DataAccessObject class. To perform advanced queries on the DB (such as SELECT with LIKE or BETWEEN...AND...) define the methods you need in your Data Access Object Class.

These classes are designed to achieve the maximum isolation between the DB structure and your application, as the table definition is contained in the custom Data Object class and nowhere else. Moreover you don't need to copy/paste code for basic operations with multiple tables, just extend the provided classes and define only what you need. That's it!

Check the examples folder for further details on how to use these classes. You'll get a much more organized code by including the ORM pattern in your application.

Content

• sources: a folder containing ORM templates and DBConnector, the class to connect to a MySQL database;
• examples: a folder containing a few usage examples of these templates; check out readme.md within each example folder.